Lawrence Craven, a doctor from the USA, is the author of several published reports, one of _______ introduced the idea in 1953 _______ aspirin could reduce the risk of heart attacks.
Rather than______ on a crowded bus, he always chooses to run to school.
---Are you sure you can pass the drving test tomorrow?. ---______. I can manage it very easily.
Terry, please _____ your cell phone when Grandma is talking to you.
It ___ we had stayed together for a couple of weeks _____I found we are very different people.
Will you go ____ our motherland needs us most after graduation?